You probally want to speak to one of the Jap company's and get them to order on your belhalf, most of the tuners don't want to bother with orders from oversea's.
I've used Greenline & OO Part, there both very good. Someone mentioned Teiwa, althogh I have used them & there is Takakara.
If you want a more UK company then Newerea would be a good bet?